Parametric study and optimization of a food can corrugation design using a response surface method

This paper presents the parametric design and functional optimization of a thin-walled food container with a corrugated surface. The configuration of the can corrugation should be designed to minimize the use of raw material subject to the constraints of the targeted structural performance. In the present study, the failure behaviors and the buckling strengths of a commercial food can under paneling pressure and axial loading are investigated with a series of experiments and finite element analyses. Full factorial design is implemented to study the effects of the geometric parameters of the corrugation (e.g., depth, radius, spacing and number of beadings) on its strength. Parameter optimization using a rotatable central composite design is employed to identify an optimal corrugation design by approximating the response surfaces of the can strength in terms of the significant design variables. The obtained surfaces are derived through the analysis of variance, and the suitability of the response is justified. A light- weight can body is then achieved by reduction of the can body thickness according to the required strength characteristics. Finite element analysis of the optimal model is also performed to confirm the predicted results. By using the proposed procedure, the can-body weight can be reduced by up to 12% compared with the original design.     

The effect of solvents on ZnS nanostructures synthesized by biomolecule-assisted solvothermal method

Nanostructured ZnS (hexagonal and cubic) were synthesized by a 200 °C and 24 h solvothermal reaction of Zn(CH₃COO)₂·2H₂O and l-cysteine (C₃H₇NO₂S) in water, propylene glycol (PG) and glycerol (GR) solvents. The products, characterized by XRD, were specified as pure ZnS (hexagonal) in water, and ZnS (cubic) in PG and GR. SEM and TEM analyses showed the particle sizes and agglomerated behaviors, mainly related to the reaction media, which were in accordance with BET adsorption of nitrogen, with blue shift energy gaps relative to the bulk.     

Suitable effective strip width of continuous bridge deck slabs system over flexible steel I-girders

Applying existing design standard provisions or analytical solutions is typically acceptable for the evaluation of slab negative moments subjected to moving traffic loads. As a breakthrough in computer technology, the finite element-based approach has become a notably versatile tool used for bridge deck analysis. In this study, a reliable finite element modeling technique is employed to discretize the models of a continuous bridge deck slab over steel I-girder system. The continuity between the girders and bridge slab has been carefully treated to ensure the overall structural action of the bridge deck. The key parameters affecting the deck slab moment such as slab system rigidity, girder spacing, patterns of moving loads and number of loaded traffic lanes are carefully considered in this study. The effective strip width concept has been used so as to take into account the evaluation of the slab negative moment. Based on the present numerical results, a set of reliable empirical formulas is proposed to determine the effective strip widths used for the direct assessment of the negative moment in a bridge deck slab. The application of these formulas is then compared with other provisions. Based on the suggested formulas, the slab reinforcement can be moderated for a common range of bridge deck proportions.     

Distribution of Elements in a Cu-Added FeSi<Subscript>2</Subscript> Alloy Under Peritectoid and Eutectoid Reactions

The distribution of Si, Fe, and Cu in FeSi₂ alloys, with or without the addition of Cu, were studied by electron probe microanalysis (EPMA). Alloys were prepared by slow solidification from the melt. Without Cu addition, both ε- and α-phases were clearly observed, and a β-phase surrounding the ε-phase was additionally observed after in situ annealing at 950°C for 12 h. With inclusion of 0.5 at.% Cu, the eutectoid reaction (α → β + Si) was enhanced greatly. Only 0.01 at.% Cu was dissolved into the ε-phase, with the excess Cu atoms being largely found at the outer edge of the ε-phase. Ex situ annealing at 950°C for 12 h greatly changed the distribution of Si, Fe, and Cu. The ε-phase changed its Si/Fe atomic ratio from 1.470 to 1.907, indicating an early stage of the peritectoid reaction (ε + α → β) and/or the subsequent reaction (ε + Si → β), with an increase in the Cu content up to 0.04 at.%. The size of this new phase was smaller than the original ε-phase, and this new phase was surrounded by a shell of Si/Fe with an atomic ratio of 0.727 to 1.788 and a Cu content of 0.01 at.% to 0.11 at.%. In situ annealing under the same condition yielded different results: a large amount of Si segregates from the α-phase matrix, leaving a Si/Fe atomic ratio of only 0.506 to 0.530. The peritectoid reaction of the ε-phase was found to depend on the Cu content. For the ε-phase with undetectable levels of Cu, the Si/Fe atomic ratio remained at 0.954 to 0.998, but this ratio decreased with increasing Cu content to 0.55 at 2.20 at.% Cu. A plot of at.% Cu versus Si/Fe atomic ratio revealed a local minimum at the ε-phase and expectedly at both the β- and α-phases. Nonstoichiometric structures (neither α-, β- nor ε-phases) seemed to have higher at.% Cu compared with those with the closest Si/Fe composition.     

Validation of Models Predicting Nucleation Rates from Induction Times and Metastable Zone Widths

Three approaches for estimation of nucleation rates from induction time and metastable zone width (MSZW) were validated based on directly measured nucleation rates for paracetamol in ethanol. To quantitatively predict nucleation kinetics using Kubota's methods it is necessary to know the minimum detectable number concentration of nuclei. This was found by determination of light transmission of a series of diluted suspensions of newly nucleated crystals where the size had already been assessed by optical reflection measurement (ORM). The measured nucleation rates strongly depended on both temperature and supersaturation. The Nyvlt method predicted nucleation rates in this system reasonably well; however, it gave slightly low estimates for all temperatures. The methods of Kubota provided nucleation rates that were low by an order of magnitude.     

Plasma prefractionation methods for proteomic analysis and perspectives in clinical applications

Plasma is a rich source of biomarkers with clinical relevance. However, the wide dynamic range of protein concentration hinders the detection of low abundance proteins. Plasma prefractionation methods serve as indispensable tools to reduce plasma complexity, allowing the opportunity to explore tissue‐derived proteins which leak into the circulation. This review summarizes common approaches in plasma prefractionation methods for proteomic analysis and then discusses some considerations in plasma prefractionation for clinical applications, reviewing some examples of its use in clinical situations.     

Preparation of LiNiVO4 nano-powder using tartaric acid as a complexing agent

LiNiVO₄ was prepared from Li₂CO₃, Ni(CH₃COO)₂·4H₂O and NH₄VO₃ using tartaric acid as a complexing agent with 1:1–1:4 mole ratios of metals:tartaric acid and subsequent calcination at 350–700 °C for 6–12 h. Inverse spinel LiNiVO₄ was detected using XRD. FTIR and Raman analyses revealed the presence of stretching band of VO₄ tetrahedrons. Only Ni, V and O were detected by EDX. The 1:4 mole ratio for the product with 450 °C calcination for 6 h analyzed by SEM, TEM and electron diffraction (ED) composes of LiNiVO₄ nano-powder with 10–30 nm in diameter.     

Hydraulic Characteristics of Gabion-Stepped Weirs

Experimental studies on the hydraulics of flow through and over gabion-stepped weirs are presented. Two flow components were observed, i.e., base flow through the void between filled stones and overflow on the gabions. The energy loss ratios in the gabion-stepped weirs are greater than those in the corresponding horizontal stepped weirs by approximately 7, 10, and 14% for weir slopes of 30, 45, and 60°, respectively. As a result, the velocity at the outlet is lower. Stone size and shape have little influence on the energy loss and flow velocity as compared to the increasing effect of the weir slope. The pressure acting on the step face for the gabion-stepped weirs is less than that of the horizontal steps owing to the cushioning effect generated by filled stones. To reduce pressure on a step face at a fixed discharge for different weir slopes, the void ratio of the filled stones should be low to allow a small amount of base flow. The pressure distribution pattern on the horizontal face of a step is provided.     

Effect of throat diameters of the ejector on the performance of the refrigeration cycle using a two-phase ejector as an expansion device

This paper is a part in a series that reports on the experimental study of the performance of the two-phase ejector expansion refrigeration cycle. In the present study, three two-phase ejectors are used as an expansion device in the refrigeration cycle. The effects of throat diameter of the motive nozzle, on the coefficient of performance, primary mass flow rate of the refrigerant, secondary mass flow rate of the refrigerant, recirculation ratio, average evaporator pressure, compressor pressure ratio, discharge temperature and cooling capacity, which have never before appeared in open literature, are presented. The effects of the heat sink and heat source temperatures on the system performance are also discussed.